Have you bothered to read the declaration? It is ambiguous at best and is obviously designed to be interpreted in such a way that only scientists who are well aware of its intended use would hesitate to sign it. Most if not all scientists believe that no scientific field should be taken on faith; questioning is the basis for discovery. At most and as written it is nothing but a list of a 'single mechanism doubters'.
I fail to see how this declaration is a net gain for anti-evolutionists since it does not declare the signers as anti-evolutionists.
P.S.: The list of scientists who are named 'Steve' that support evolution is a whole lot bigger than DI's little list so if you intend on applying DI's list in some misguided appeal to authority it can be easily countered.
Too bad you fail to see this as a sign that we are winning. Of course, many Democrats failed to see faith as a winning block of voters in 2004; e.g., a winning block of Conservative SCOTUS judges that will vote to overturn the bigotry against Creation being taught along side Evolution in our schools.